Angle oscillating power drive for rotating or swinging a hinged member

ABSTRACT

A rotary drive for swinging a heavy member between two extreme positions. The drive transmits a rotary force provided by a motor or similar device through a first rotatable shaft to a second rotatable shaft perpendicular to the first shaft and connected to the heavy member. The second shaft rotates in an oscillatory manner between the extreme positions in response to rotation of the first shaft. The member may thus be positioned at any suitable location in its travel by operating the motor unidirectionally. The first shaft rotates about a first axis of rotation and rotates an arm about a second axis of rotation that intersects the first axis at an angle between zero and 90 degrees non-inclusive. The arm is connected to a universal joint having three mutually perpendicular axes. The universal joint transmits forces from the arm to the second shaft.

BACKGROUND OF THE INVENTION

The present invention relates generally to rotary drives or actuatorsfor swinging or rotating relatively heavy hinged objects such assecurity gates and, more specifically, to such a drive that converts acontinuous rotary force into an oscillatory rotary force.

Right angle drives are used to transmit a rotary force from a firstrotating member to a second rotating member disposed at a right angle tothe first member. Right angle drives may include worm gears or crowngears. Such drives are commonly used in combination with reductiongearing in aircraft landing gear actuators and similar actuators.

It is desirable to reverse an actuator, such as an aircraft landinggear, that includes a right angle drive. To reverse such an actuator,either the motor that generates the rotary force must be reversed or theactuator must be provided with complex gearing.

Certain conventional right angle drives transmit force applied to thefirst rotating member to the second rotating member equally asefficiently as they transmit force from the second rotating member towith the first rotating member. In an actuator such as those used onlanding gear, however, it is desirable to prevent landing forcesexperienced by the landing gear wheels from rotating the drive and motorand thereby collapsing the landing gear.

These problems and deficiencies are clearly felt in the art and aresolved by the present invention in the manner described below.

SUMMARY OF THE INVENTION

The present invention comprises a rotary drive for transmitting a rotaryforce generated by a motor or similar device from a first rotatableshaft to a second rotatable shaft perpendicular to the first shaft andconnected to a heavy swingable member, such as a security gate, door, oraircraft landing gear. The second shaft rotates in an oscillatory mannerin response to rotation of the first shaft. The first shaft rotatesabout a first axis of rotation and rotates an arm about a second axis ofrotation that intersects the first axis at an angle between zero and 90degrees non-inclusive. The arm is connected to a universal joint havingthree mutually perpendicular axes. The universal joint transmits forcesfrom the arm to the second shaft.

The universal joint comprises a rotary coupling or slip joint and ahinge or pivotal joint. The first and second sides of the rotarycoupling rotate with respect to each other about a second axis thatintersects the first axis at a predetermined angle of between zero and90 degrees non-inclusive, but preferably between about 30 and 60degrees. An arm connects the first shaft to one side of the rotarycoupling. The word "arm" is used herein only for convenience and isintended to include, in addition to elongated members, members of anysuitable shape that can connect the rotary coupling to the first shaftat the predetermined angle, such as a wedge-shaped member. The hingerotatably or pivotally connects the second side of the rotary couplingto the second shaft. The hinge rotates about the third axis, and thesecond shaft rotates about the fourth axis.

In operation, rotating the first shaft drives the arm in a crank-likemanner. The second axis traverses a conical area having a vertex at thefourth axis. In response, the second shaft rotates in an oscillatorymanner about the fourth axis. The second shaft is at the centralposition or minimum of its oscillation cycle when the first and thirdaxes are perpendicular. As the second axis traverses the conical area,the third axis rotates away from this central position. The second shaftis at one of the limits or maxima of its oscillation cycle when thethird axis has rotated away from the central position by an angle equalto the predetermined angle between the first and second axes.

The drive may be used to move or swing or rotate a member connected tothe second shaft. Although the drive may be used in mechanisms in whichit oscillates a member, the drive is particularly useful in actuators inwhich it moves a relatively heavy member to one of two extremepositions, such as aircraft landing gear and control surface actuatorsand security gate actuators.

The drive of the present invention facilitates the design of economicalactuators having control mechanisms of minimal complexity and number. Tomove a member from one extreme position to the opposite extremeposition, such as to extend a landing gear or open a gate, the motor orsimilar means for generating a rotary force may be operated for a shortperiod. To return the member to its starting position, such as toretract the landing gear or close the gate, the motor may be operatedfor the same short period and in the same direction of rotation; themotor need not be reversed. In addition, the drive amplifies the forcegenerated by the motor. An economical, non-reversible, relativelylow-power motor may therefore be used to swing relatively heavy members.

The drive of the present invention also prevents rotary forcesexperienced by the second shaft from rotating the first shaft. In anyposition of its travel, the drive is essentially locked againstundesirable movement.

In addition, the drive of the present invention can move a driven membersmoothly and efficiently between the limits of its travel. The secondshaft rotates more slowly toward the limits of its travel and morerapidly as it passes its central position because its motion is harmonicor sinusoidal. The driven member, such as a landing gear or a gate, isautomatically decelerated as it nears the extreme position and is thusgently maneuvered into position. The driven member therefore tends notto overshoot the desired position. Stress and wear on moving parts isminimized.

Furthermore, the range of travel of a driven member connected to thesecond shaft can be selected by selecting the predetermined anglebetween the first and second axes. The second shaft will traverse anangle that is twice the predetermined angle between the first and secondaxes. If the first and second axes intersect at an angle of 45 degrees,for example, the second shaft will rotate 45 degrees in either directionfrom its central position for a total range of travel of 90 degrees.

The foregoing, together with other features and advantages of thepresent invention, will become more apparent when referring to thefollowing specification, claims, and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following detailed description of the embodimentsillustrated in the accompanying drawings, wherein:

FIG. 1 is a side view of the drive installed in a security gateactuator, with the gate shown in a closed position;

FIG. 2 is an enlarged sectional view taken on line 2--2 of FIG. 1;

FIG. 3 is an enlarged sectional view taken on line 3--3 of FIG. 1, withthe gate driven to the half open position;

FIG. 4 is a view similar to FIG. 3, but with the gate driven to thefully open position;

FIG. 5 is a side elevation view of an alternative drive installed in asecurity gate actuator, with the gate shown in a closed position;

FIG. 6 is an enlarged sectional view taken on line 6--6 of FIG. 5;

FIG. 7 is an enlarged sectional view taken on line 7--7 of FIG. 5, withthe gate driven to the half open position; and

FIG. 8 is a view similar to FIG. 7, but with the gate driven to thefully open position.

DESCRIPTION OF PREFERRED EMBODIMENTS

As illustrated in FIG. 1, the drive 10 of the present invention isinstalled in a gate actuator, which further includes a suitable motor 12and reduction gearing 14. Motor 12 constitutes an exemplarynon-reversing motive means for generating a unidirectional rotary force.Motor 12 and reduction gearing 14 transmit rotary force to a first shaft16. Drive 10 converts the rotary force it receives via first shaft 16 toan oscillatory rotary force and applies it to a second shaft 18. Thegate actuator can open and close a heavy, generally planar member, suchas a gate 20, which is connected to second shaft 18, as described below.

Drive 10 is illustrated in further detail in FIG. 2. Drive 10 comprisesa wedge-shaped arm 22 and a rotary coupling 24. Rotary coupling 24 andsecond shaft 18 cooperate to form a universal joint that allows arm 22to move freely with respect to three mutually perpendicular axes. Firstshaft 16, which is rotatable about a first axis of rotation (not shown),is connected to wedge shaped arm 22. Coupling 24 is pivotally orhingedly retained in a housing 25 by two hinge pin bolts 26 and 28 thatextend through bearing bores in opposing walls of housing 25. Housing 25is preferably welded in place in shaft 18, although it may be connectedto shaft 18 in any other suitable manner, such as by forming housing 25integrally with shaft 18 or by fastening housing 25 to shaft 18.

Coupling 24 comprises an annular or toroidal member 30 retained betweentwo disc-shaped retainer plates 32 and 34. A plurality of rollerbearings 36 are retained in opposing bearing races in plates 32 and 34and in toroidal member 30 and facilitate relative rotation betweenplates 32-34 and toroidal member 30 about a second axis of rotation (notshown). In the illustrated embodiment, this second axis of rotationintersects the first axis of rotation at an angle of 45 degrees. A bolt38 extends through plate 32, toroidal member 30, and plate 34, andsecures coupling 24 to arm 22. Hinge pin bolts 26 and 28 are received inthreaded bores in toroidal member 30 and facilitate rotation or pivotingof coupling 24 about a third axis of rotation with respect to housing 25and shaft 18. The portion of housing 25 from which arm 22 extends isopen to prevent housing 25 from interfering with the motion of arm 22.

As illustrated in FIGS. 3 and 4, shaft 18 is rotatable about a fourthaxis of rotation (not shown) that is perpendicular to the first, secondand third axes of rotation. Rotation of shaft 18 moves gate 20 betweenopen and closed positions. The gate is shown in the closed position inFIG. 2. Rotation of first shaft 16 in the direction of arrow 40 causessecond shaft 18 and gate 20 to rotate in the direction of arrow 42. Ifshaft 16 were continuously rotated at a constant velocity, shaft 18 andgate 20 would oscillate between the position shown in FIG. 2 and theposition shown in FIG. 4 in a sinusoidal or harmonic manner. Shaft 18 isshown in the central position of its oscillation cycle in FIG. 3.

Another embodiment of the invention is illustrated in FIGS. 5-8. Asillustrated in FIG. 5, a drive 44 of the present invention is installedin a gate actuator in the same manner as in the embodiment describedabove with respect to FIGS. 1-4. Drive 44 converts the rotary force itreceives via a first shaft 46 to an oscillatory rotary force and appliesit to a second shaft 48. The gate actuator can open and close a gate 50,which is connected to second shaft 48, as described below.

Drive 44 is illustrated in further detail in FIG. 6. Drive 44 comprisesa crank-like arm 52 and a rotary coupling 54. Rotary coupling 54 andsecond shaft 48 cooperate to form a universal joint that allows arm 52to move freely with respect to three mutually perpendicular axes. Firstshaft 46, which is rotatable about a first axis of rotation 80, isconnected to crank-like arm 52. Crank-like arm 52 comprises a disc 56and an elongated member, such as a crank 58. The proximal end 84 ofcrank 58 is connected to a point on disc 56 spaced radially away fromthe first axis of rotation. The distal end 86 of crank 58 is connectedto coupling 54. Coupling 54 comprises an exemplary first hinge portion,described in further detail below, and is pivotally or hingedly retainedin a cylindrical housing 60 by a second hinge portion, such as a hingepin 62 that extends through bearing bores in opposing walls of housing60. Housing 60 is preferably welded in place in shaft 48, although itmay be connected to shaft 48 in any other suitable manner, such as byforming housing 60 integrally with shaft 48 or by fastening housing 60to shaft 48.

Coupling 54 comprises an annular or toroidal member 64 retained in acup-shaped body 66, which defines the exemplary first hinge portionnoted above. A plurality of ball bearings 68 are retained in opposingbearing races 78 in toroidal member 64 and body 66 and facilitaterelative rotation between member 64 and body 66 about a second axis ofrotation 74. In the illustrated embodiment, this second axis of rotationintersects the first axis of rotation at an angle of 45 degrees. Asdescribed above, coupling 54 pivots or rotates on hinge pin 62 about athird axis of rotation 76. The portion of housing 60 from which arm 52extends has an opening 69 to prevent housing 60 from interfering withthe motion of arm 52.

As illustrated in FIGS. 7 and 8, shaft 48 is rotatable about a fourthaxis of rotation 82 that is perpendicular to the first, second and thirdaxes of rotation. Rotation of shaft 48 moves gate 50 between open andclosed positions. The gate is shown in the closed position in FIG. 6.Rotation of first shaft 46 in the direction of arrow 70 causes secondshaft 48 and gate 50 to rotate in the direction of arrow 72. If shaft 46were continuously rotated at a constant velocity, shaft 48 and gate 50would oscillate between the position shown in FIG. 6 and the positionshown in FIG. 4 in a sinusoidal or harmonic manner. Shaft 48 is shown inthe central position of its oscillation cycle in FIG. 7.

Obviously, other embodiments and modifications of the present inventionwill occur readily to those of ordinary skill in the art in view ofthese teachings. Therefore, this invention is to be limited only by thefollowing claims, which include all such other embodiments andmodifications when viewed in conjunction with the above specificationand accompanying drawings.

What is claimed is:
 1. A drive for swinging a heavy member between twoextreme positions, comprising:non-reversing motive means for generatinga unidirectional rotary force; reduction means connected to said motivemeans for reducing a speed of said rotary force; a first shaft rotatableabout a first axis of rotation, said first shaft connected to saidreduction means; an arm connected to said first shaft; a universal jointconnected to said arm, said universal joint having second, third andfourth mutually perpendicular axes of rotation, said second axis ofrotation intersecting said first axis of rotation at a predeterminedangle between zero and 90 degrees; and a second shaft connected to saidheavy member and rotatable about said fourth axis of rotation andconnected to said universal joint, said fourth axis of rotationperpendicular to said first axis of rotation.
 2. The drive claimed inclaim 1, wherein said second shaft comprises a hollow housing portion,and said universal joint is disposed within said housing portion, saidarm extending through an opening in said housing portion.
 3. The driveclaimed in claim 1, wherein said extreme positions are defined inresponse to said predetermined angle.
 4. The drive claimed in claim 3,wherein said predetermined angle is between 30 degrees and 60 degrees.5. A drive, comprising:an arm comprising an elongated member rigidlyconnectable to a first shaft having a first axis of rotation; a firstcoupling portion connected to said arm; a second coupling portionrotatably connected to said first coupling portion for rotation about asecond axis of rotation, said second axis of rotation intersecting saidfirst axis of rotation at a predetermined angle between zero and 90degrees; said elongated member having a proximal end disposedeccentrically with respect to said first axis of rotation andsubstantially aligned along said first axis of rotation and having adistal end substantially aligned along said second axis of rotation; afirst hinge portion rigidly connected to said second coupling portion;and a second hinge portion rotatably connected to said first hingeportion for rotation about a third axis of rotation perpendicular tosaid second axis of rotation, said second hinge portion rigidlyconnectable to a second shaft having a fourth axis of rotationperpendicular to said first, second and third axes of rotation.
 6. Thedrive claimed in claim 5, wherein said arm further comprises a discconnected to said proximal end of said elongated member foreccentrically disposing said proximal end with respect to said firstaxis of rotation.
 7. The drive claimed in claim 5, wherein said distalend of said elongated member is connected to said first couplingportion.
 8. The drive claimed in claim 7, wherein said first hingeportion comprises a cup-shaped housing, and said first and secondcoupling portions are concentrically disposed in said cup-shapedhousing.
 9. The drive claimed in claim 8, wherein:said first hingeportion further comprises a pin; and said second hinge portion comprisesa hollow housing having opposing bearing openings therein for rotatablyreceiving said pin.
 10. The drive claimed in claim 8, further comprisinga plurality of ball bearings retained between said first and secondcoupling portions.
 11. The drive claimed in claim 5, wherein saidpredetermined angle is between 30 degrees and 60 degrees.
 12. The driveclaimed in claim 11, wherein said predetermined angle is approximately45 degrees.